The Lingering Psychological Effects of Multiple Sex Partners

The mental health consequences of having multiple sex partners were long thought to include greater rates of anxiety and depression. At the same time, high rates of alcohol and substance abuse were thought to increase the chances of young adults engaging in unsafe sex with multiple partners. New research from a longitudinal study of over 1,000 New Zealanders shows that, surprisingly, neither of these assertions is true.

The majority of studies citing a relationship between mental health problems, including substance and alcohol use, and number of sex partners are correlational in nature. As a result, it’s impossible to tell whether people seek sex partners in an effort to “self-medicate;” in other words to reduce the emotional pain they are experiencing, by seeking sexual connections with others, even if fleeting. The correlation-does-not-equal-causation problem in these studies also means that people with a high-risk lifestyle both seek sexual liaisons and substance use either because they have impulsive personalities or because they are anxious and depressed. The considered wisdom from such research, problematic as it was, led mental health experts to argue that in order to reduce the rates of risky sexual behavior, it’s necessary to treat the underlying psychological issues that lead individuals to these outlets for their unhappiness or personality styles.

An international team of mental health researchers headed by Dunedin School of Medicine’s Sandhya Ramrakha and colleagues (2013) were uniquely positioned to test the causal directions of the multiple sex partner-mental health connections. The Dunedin Multidisciplinary Health and Development Study was begun in the mid-1970s on a cohort of over 1,000 children consisting of 90% of the children born between 1972 and 1973. They were followed every 2 years until they were 15 and then again at ages 18, 21, 26, and 32. An amazing large percentage (96%) remained available for testing over that 30-year period. At ages 21, 26, and 32, they were given individual assessments on their mental health status in the areas of anxiety, depression, and substance (cannabis and/or alcohol) dependence. They were asked to report on the number of sex partners at each interval as well, allowing the researchers to compute the number of partners per year. With these data in hand, Ramrakha and team were able to calculate the odds of a participant developing a psychological disorder while controlling for earlier mental health problems at each test occasion.

For both men and women, taking into account prior psychological disorders, the odds of developing substance dependence increased virtually linearly with the number of sex partners. The relationship was particularly pronounced, however, for women. People having a higher number of sex partners did not have higher rates of anxiety or depression; the mental health effects were limited to substance use.

You might be wondering how multiple is multiple in the sex partner equation. The sample distribution led the researchers to divide the number of partners into 3 groups on a yearly basis: 0 or 1, 1.1-2.5, and 2.6 or over. However, some participants reported more than 10 in a given year.

The authors acknowledge that, even though they ruled out the effects of prior substance use on number of sex partners, the possibility remains that people living a risky lifestyle have a higher number of sex partners and, later on, develop mental health problems. It’s also possible that people who are having sex with multiple partners are in situations where alcohol and drugs are around, and therefore, will be the ones to develop substance dependence over time.

The nature of casual sex relationships may, however, present a risk factor in and of itself. These relationships may be particularly likely to be impersonal, lacking in the potential to provide emotional fulfillment. People having a string of these relationships may turn to the self-medication provided by alcohol or drugs. As the authors point out, drinking alcohol to cope with feelings of loneliness and despair can pave the way for later substance dependence.

Although women and men are developing similar patterns of sexual behavior and substance use, particularly in this cohort, the effects were stronger for women, as I noted earlier. It appears that the double standard is still alive and well. For women, having multiple sex partners still may go against what they regard as socially acceptable. They cope with their feelings of shame, embarrassment, and perhaps dissatisfaction by turning to the solace of alcohol and drugs, setting them up for the future development of a substance use disorder.

The upshot of this fascinating study is that if you, or someone you know, is involved in a series of casual or fleeting relationships, it’s important to realize that there may be alcohol or drug dependence consequences down the road. The issue is particularly important for young women. The double standard is probably not going away anytime soon. Therefore, women in particular might want to consider their reasons for becoming involved in frequent sexual pairings, and even more importantly, their feelings the morning after. The purpose of research such as Ramrakha’s and colleagues is not to scold people for having multiple partners or add to the guilt of those who already feel that they’re violating their own moral standards. Instead, it’s to point out that, from a strictly scientific standpoint, engaging in frequent sex with multiple partners does seem to carry a risk.

The benefits of a long-term study that follows people over the critically formative early years of life is that we can learn about ways to prevent mental health problems for people as they navigate the stressful years of early adulthood. With this knowledge, young adults, along with their parents and counselors, can perhaps be better prepared to seek intervention and pave the way for a less troubled, and more fulfilling, life to follow.

Follow me on Twitter @swhitbo for daily updates on psychology, health, and aging. Feel free to join my Facebook group, "Fulfillment at Any Age," to discuss today's blog, or to ask further questions about this posting.

"For women, having multiple sex partners still may go against what they regard as socially acceptable. They cope with their feelings of shame, embarrassment, and perhaps dissatisfaction by turning to the solace of alcohol and drugs, setting them up for the future development of a substance use disorder."

I don't think this is necessarily just a question of a double standard. It could also be that having multiple sexual partners is more fulfilling for men than it is for women, and that could be why women with this lifestyle are more likely to turn to addicting substances.

The author's idea is more valid. The amount of fulfillment people get out of their sexual lifestyle depends on many factors and there is great variation from one woman to another, same as for men. I think we need to stop thinking female vs. male in terms of sexuality; it's counterproductive and propagates the "double standard" the author is talking about.

Recognizing that sexual behavior is dependent on a myriad of factors for every individual, with gender simply being one, albeit an important one, seems to be the way forward.

Frequently men have girlfriends and marry women who cheat on them anyway, so what's the difference? Plenty of men raise another man's child without knowledge!

Women aren't that different to men, because we are single and we like sex should we stay celibate until Mr Right comes knocking?!

Nope you shouldn't stay celibate at all. Just have sex with me and when I run off on your dumb ass and leave you in tears. You can find some other idiot to raise and foster MY DNA into the future. Then I get to continue spreading my seed and some dumb ass gets to pay for MY DNA's future and not his.

Are you so dense that you don't know the difference. I hope you are just ignorant and not stupid. Do you need someone to explain the difference between ignorance and stupidity too?

Lets assume you are just ignorant.

The difference is that the female always knows her child is hers and the male does not. This is an extremely unfair advantage for the female. This is the reason for SLUT shaming. Slut shaming helps to bring this biological advantage back into balance.

Want fairness. Then we need a legal system that forces DNA paternity test upon the birth of a new baby. A man deserves the right to walk away from a SLUT without being called insecure for it. No man alive should have to pay for another mans DNA if he chooses not to.

Women want a fair shake, then give the men the same knowledge you get as far as knowing who the parents are. Or else shut up your freaking bitching and learn to deal with being called a slut.

Hi Susan,
The results you reported don't support your interpretation of the data. You stated that people with more sex partners did NOT experience elevated anxiety and depression. If they had feelings of shame and embarrassment, wouldn't you predict greater anxiety and depression?

A more parsimonious explanation for the data is that people who are more approach-motivated have more sex partners and are more likely to abuse substances.

Dear Sibyl, The authors of the study offered this interpretation but they consistently emphasized that over the period of the study they did not observe increased risk of anxiety and depression. The other point you made is a good one, which they also discussed, but based on the findings, they reached a different conclusion. If you'd like to see the original article, let me know and I can send it to you. Thank you for your comment! Best, Susan

Hi Susan,
I just downloaded and read the full original study. All it showed was that people who admit having more sex partners admit to having substance abuse problems later in time.

1. This is just a correlational study. Authors of this kind of longitudinal study like to make it sound like things that happen later in time (substance abuse) are caused by whatever they measured earlier in time (number of sex partners). But there's actually no evidence of a causal relationship.

2. The number of sex partners a person has and how much drinking or drugging a person does are very easy to lie about. Most women under-report their number of sex partners. Most people of both genders lie (under-report) about how much they drink and whether they use drugs. The relationship shown in this article may be nothing more than response bias. In other words, people (especially women) who are honest about having sex with multiple partners are also forthcoming about their substance use.

3. In the discussion, the authors admit that greater approach motivation (which they call 'impulsiveness') could account for their results. They don't present a shred of evidence against this perfectly plausible explanation, but they launch into unsupported speculation about 'interpersonal anxiety.' Well, why didn't this so-called anxiety show up in their measures?

Bottom line: the original article did not provide good evidence of causation. It also did not provide any evidence for a cause of the correlation between sex partners and substance abuse.

Hi again Sybil,
Although this was not an "experimental" study (no one will ever be able to conduct that one), I stand by the findings because it was such a remarkably well-controlled longitudinal investigation. However, I do see your point. Next week I plan to write a follow-up that reviews the factors contributing to an impulsive/high-risk lifestyle, which will address some of the issues you've raised. Again, thank you for sharing your comments and keeping the discussion going. Best, Susan

The study found that people who had more sex partners when they were young had more drug/alcohol problems later. Then they claimed that the greater number of sex partners caused the drug problems. It's like if they found that people who eat cereal in the morning are more likely to eat fast food for dinner, and then claimed that eating cereal *causes* you to eat fast food. Of course, the reality would be that the cereal-eating didn't cause anything. Instead, people who like convenient foods eat both cereal and fast food.

Just because one event precedes another in time does not mean that the first even caused the second. This is basic stuff.

I find it strange that nothing was said about sexually transmitted disease/infections. Both could have a significant impact on depression/anxiety and substance abuse. If I caught the HIV I would be appropriately saddened by the fact; If I had gonorrhea I would probably pop a vicodin. I can easily see how both could evolve in severity, that coupled with the fact that your chance of catching something rises exponentially with the number of sex partners, you know 2+2, more sex partners=possibly higher rates of sti/std=possibly higher depression and/or drug abuse.

Dear Andrew, There was discussion about these in the original article, but to keep this to a reasonable length, I had to condense things. This is an excellent point. If you would like to see the original article, let me know by backchannel and I will send it to you. Best, Susan

I'm right with you on the theory that women who are interested in sex with higher numbers of partners are subject to feelings of lower self-esteem when they compare themselves with societal expectations of "proper" female sexual behavior. The idea that more partners equals more drug use and could be tied to that is interesting.
I wonder if there's some kind of control group out there anywhere. As in, women who have a lot of partners but don't have any drug issues and why they're more resilient/resistant, or women who don't have a lot of partners but still have drug trouble.

I wonder if the study included categories for types of drugs turned to by the women, stimulants vs. depressants vs. hallucinogens etc. My theory is that there's a group of people who are "hungrier" for experiences of all types, sexual and pharmacological as well as others and perhaps that is the group of women the study zeroed in on. There's certainly a group of males that parallel.

There may be a genetic/biological trend that these women share. Do you really think that internalized feelings of stigmatization lead more promiscuous women to drugs? That double standard needs to go extinct if that's the case. Along with many other reasons, of course.

The neurophysical consequences were not examined. The women could very well be experiencing depression and anxiety from having a higher number of sexual partners because of the effects of oxytocin and the desire for bonding it instills, with the subsequent lack of bonding on offer from an unattached partner. In other words, there may be a biological basis rather than just a cultural one.

I am a middle-aged woman who has been single-again for +20 years. The number of sex partners over the years has slowed down, but I believe it exceeds 300 men. (And no, I never caught anything from any of them - not even a cold!) I have never had a drug (OK, Novocaine at the dentist's) nor even a glass of alcohol in my entire life. I am not an anxious person. I don't perceive myself as chronically depressed, and if I were, I'd be LESS likely to engage in sexual activity than more. I have never worked in the sex industry. Since I became a teen, I've been called "boy crazy." As a mature woman now, having had a (very bad) marriage early in life, I have consciously chosen not to remarry, partly because there "are so many interesting flowers in the garden." I think the conclusions the researchers have obtained in this study are not even logical. Perhaps in that cohort, their generalizations could be correct. But I suspect there are a LOT of people like me living at the far edges of the Bell curve. More than any researcher has yet discovered!

300 men???! That's disgusting, and if you admit that to any prospective date, they will think as I do, like it or not. This is not some cultural creation; it's deep-seated psychology / physiology based on evolution.

I could not understand how these conclusions were drawn. I also read a very shaming tone in this piece, assuming that having multiple sexual partners is unhealthy for women. I think we need to look at the double standards that are implicit in this piece (that women having multiple sexual partners would lead to negative consequences for their mental health) and also allow for the fact that women may find sex pleasurable, even with the hangover effect of shame that is all too common in this culture.

And how do you think this 'cultural' "double standard" arose? BIOLOGY. Men on average are INNATELY less attracted to women who have had many partners. Now before anyone blasts me for 'shaming' or what-have-you, note that I agree you that this is not FAIR. But nature doesn't operate on the basis of fairness, and a study that points out an unfortunate reality doesn't make it less true.

Double-standards can only exist when the two are equal. Until a woman realizes she is not the equal of a man, nor he of she, then they shall never understand which is correct answer above. Mother Nature is fact; the female social contructs are horse-s-h-i-t.

"The double standard is probably not going away anytime soon. Therefore, women in particular might want to consider their reasons for becoming involved in frequent sexual pairings, and even more importantly, their feelings the morning after."

This assumption is not only pessimistic, but problematic as well. It's basically saying that because society makes it shameful for women to sleep around, women will develop psychological issues from doing so, and therefore should just conform/avoid having multiple sexual partners.

Of course this is just anecdotal, but I know plenty of women who have had multiple sexual partners and are perfectly psychologically healthy and have high self-esteem. I also know women who feel ashamed about having slept with multiple partners, and would potentially be at risk for substance abuse, but I don't think the solution is just to avoid casual sex. If there's a more deeply rooted societal influence at play (i.e. the double standard), simply accepting it and adapting to it is going to get us anywhere. The double standard is not inevitable or permanent, and suggesting so merely propagates it.

Susan, I think this is a fascinating topic. I'd have to think more about what I think about the real-life validity of the argument the research posits, but I think that discussing the issue regardless is fascinating and important!

It seems to me that if you go into a study looking for pathology that will support your values or beliefs, it's not hard to find it. One alternative explanation that might be true in some cases is that the substance abuse is to medicate the societally imposed shame and inner conflict, and not as the result of a pathology that the sexual promiscuity itself causes. I agree with the woman who wrote "illogical correlation" that some people are just different and it is in their nature to want many sexual partners, but there is a tendency in humans to want to see the "normal" as equivalent to "healthy" (i.e. the "good Christian") and the "abnormal" to be the same thing as "unhealthy" (the "sinner"). This way of thinking can be easily debunked by looking into different historical periods and different cultures where the "normal" was opposite or very different than "normal" today.

New Zealand does not have a 'dating' culture like the US we have a binge drinking culture. So as a young person you go to a party get drunk have sex and then mostly enter a relationship with that person. You probably fancied the person you had sex with previously but were too shy to mention it to them before you got drunk and had sex. This system works people get married from it. The women getting blind drunk and having sex with people she doesnt want to secretly go out with always had a substance abuse problem it is just in our culture it isneasy to go unnoticed until middle age.

Why... pray tell... is it so far fetched to believe that physically and mentally healthy, well adjusted, happy women would have multiple sex partners without guilt, regret, and addiction afterward? Partners who are multiple in number but none the less carefully chosen before a sexual act occurs. Women who have multiple partners just simply for the fun of enjoying the body and the company of someone you like and are attracted to without the commitment? I am not a unicorn, nor a unique little snowflake in this. I am a 40 year old woman with many friends who are successful, NOT regretful, NOT filled with guilt, NOT addicted to alcohol and drugs, with healthy self esteem, who simply enjoy their sexuality and express this by having friends with benefits. Not only is this study biassed, but the article is as well as the data reported in merely correlational in nature. Seriously folks...

This is an interesting report and topic. Also interesting to see how defensive people get about this topic, expressing their resistance to the content actually tells us something important about them.

One point that stood out to me, was that while the article assumes individual choice on the part of the participants, it suddenly switched to "society is at fault" reasoning for negative choices women make regarding alcohol and drugs. To me that read like a cop out. Every person is free to choose and I can't really blame others for my poor choices.

I can't comment on others' but I have been with one woman for 36 years and only intimate with her. My heart/mind is so tied into hers I can't imagine breaking that intimacy bond with anyone else, for a physical act.

Maybe it isn't society that makes me feel there is something amiss after multiple partners. Maybe it is within my own brain that tells me what I am doing is not satisfying, and is actually hindering my ability to connect to another. Feeling that loss of connection then actually fuels the desire to connect and so more partners seems like the answer - but is in fact feeding the issue.